1. Field of the Invention
The present invention relates to software tools for facilitating packaging design. More specifically, the present invention relates to a design methodology that employs a software design tool to generate a module based substrate design.
2. Description of the Prior Art
In a semiconductor device package, a semiconductor chip (also referred to as an integrated circuit (IC) chip or “die”) may be bonded directly to a substrate. Such a die is formed with ball-shaped beads or bumps of solder affixed to its I/O (input/output) pads. During packaging, the die is “flipped” onto its front surface (e.g., active surface) so that the bumps form electrical connections between the die and conductive electrical pads on a substrate. A semiconductor device package of this type is commonly called a “flip chip package”.
Generally, the substrate includes a complex design of electrical interconnects that electrically connect the conductive electrical pads on one side of the substrate with ball grid array (BGA) lands on another side of the substrate. Different routing approaches are currently used that affect the design of the electrical interconnects. One approach is to perform a manual interconnect routing that allows each designer to route the electrical interconnects such that routing density can be maximized. The design of the electrical interconnects is often left to the discretion and idiosyncrasies of the individual designer. Not only can this result in inconsistent design results between different designers with different levels of expertise, but it can also be time consuming.
In an attempt to standardize design results between different designers, another approach is to perform a constraint driven interconnect routing. Constraint driven interconnect routing applies certain electrical requirements to the routing of the electrical interconnects. Although constraint driven interconnect routing provides some standardization, it is often difficult to standardize throughout the electrical interconnects with the constraints. Furthermore, the results still depend on the individual designer's level of expertise.
Yet another approach is to use any number of commercially available software design tools to perform an auto interconnect routing. However, the use of auto interconnect routing is usually limited to very simple electrical interconnect designs where the results are often unpredictable. Moreover, routing density is usually not maximized. Thus, even though some exemplary automated design tools exist, there are still considerable inefficiency and ineffectiveness in the achieved results and in the way that designs are implemented.
Consequently, it is therefore desirable to provide improved methods and apparatus for designing the electrical interconnects of a substrate. More specifically, it is desirable to provide techniques and mechanisms for efficiently and effectively generating a standardized electrical interconnect design.